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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.server.firewall;
import android.content.ComponentName;
import android.content.Intent;
import android.net.Uri;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
class PortFilter implements Filter {
private static final String ATTR_EQUALS = "equals";
private static final String ATTR_MIN = "min";
private static final String ATTR_MAX = "max";
private static final int NO_BOUND = -1;
// both bounds are inclusive
private final int mLowerBound;
private final int mUpperBound;
private PortFilter(int lowerBound, int upperBound) {
mLowerBound = lowerBound;
mUpperBound = upperBound;
}
@Override
public boolean matches(IntentFirewall ifw, ComponentName resolvedComponent, Intent intent,
int callerUid, int callerPid, String resolvedType, int receivingUid) {
int port = -1;
Uri uri = intent.getData();
if (uri != null) {
port = uri.getPort();
}
return port != -1 &&
(mLowerBound == NO_BOUND || mLowerBound <= port) &&
(mUpperBound == NO_BOUND || mUpperBound >= port);
}
public static final FilterFactory FACTORY = new FilterFactory("port") {
@Override
public Filter newFilter(XmlPullParser parser)
throws IOException, XmlPullParserException {
int lowerBound = NO_BOUND;
int upperBound = NO_BOUND;
String equalsValue = parser.getAttributeValue(null, ATTR_EQUALS);
if (equalsValue != null) {
int value;
try {
value = Integer.parseInt(equalsValue);
} catch (NumberFormatException ex) {
throw new XmlPullParserException("Invalid port value: " + equalsValue,
parser, null);
}
lowerBound = value;
upperBound = value;
}
String lowerBoundString = parser.getAttributeValue(null, ATTR_MIN);
String upperBoundString = parser.getAttributeValue(null, ATTR_MAX);
if (lowerBoundString != null || upperBoundString != null) {
if (equalsValue != null) {
throw new XmlPullParserException(
"Port filter cannot use both equals and range filtering",
parser, null);
}
if (lowerBoundString != null) {
try {
lowerBound = Integer.parseInt(lowerBoundString);
} catch (NumberFormatException ex) {
throw new XmlPullParserException(
"Invalid minimum port value: " + lowerBoundString,
parser, null);
}
}
if (upperBoundString != null) {
try {
upperBound = Integer.parseInt(upperBoundString);
} catch (NumberFormatException ex) {
throw new XmlPullParserException(
"Invalid maximum port value: " + upperBoundString,
parser, null);
}
}
}
// an empty port filter is explicitly allowed, and checks for the existence of a port
return new PortFilter(lowerBound, upperBound);
}
};
}
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